Supercharged internal combustion engine



June 2 1942 E. I. B. .MARPLES Erm.

SUPERCHARGED INTERNAL COMBUSTION ENGINE Filed Feb. 15, 1941 6 Sheets-Sheet 1 Ina/71231: Elwyn I. Jfarpies J1me 1942. E. 1. B. MARPLES ETAL 2,285,344

SUPERCHARGED INTERNAL COMBUSTION ENGINE 7 Filed Feb. 15, 1941 s Sheets-Sheet 2' im/23m El Z .J% Z9: (2% 023%; M 57 zww W u Zzzrrwya u 1942- E. 1. B. MARPLES ETAL 2,285,344

v SUPERCHARGED INTERNAL COMBUSTION ENGINE Filed Feb. 15, 1941 s Sheets-Sheet s w 27 I f r 'Z- June 2, 1942.

E. 1. B. MARPLES ETAL 2,285,344

SUPERCHARGED INTERNAL COMBUSTIONENGINE Filed Feb. 13, 1941 1750 11B. @2 0 s 137i; 7% orrezl 6 Sheets-Sheet 4 PatentedJune 2, 1942 Elwyn Ivo Banks Marples and Horace Nathaniel Gorrell, Bristol, England, assignors to The Bristol Aeroplane Company Limited, Bristol, England, a British company Application February 13, 194 1,"'Selial No; 378,826

In Great Britain February 13, 1940 10 Claims. (01. 123-119)- This invention relates to supercharged internal-combustion engines, for aircraft, of the kind comprising two blowers in series, at least one of which can be rendered operative or inoperative at will, and acarburettor between the blowers. For example, the second-stage blower may be permanently geared to the engine and the firststage blower may be driven from the engine through clutch-mechanism which may be engaged or disengaged at will. Alternatively, the first-stage blower maybe driven by a turbine through which the exhaust gases of the engine are discharged; in this case the first-stage blower may be rendered inoperative by by-passing the exhaust gases so that they aredischarged without driving the turbine. At low altitudes of flight the first-stage blower is out of action and the combustion air merely passes through it to the carburettor and second-stage blower. Above a certain altitude of flight the pilot renders the first-stage blower operative whereby the extent of supercharge is increased. f

The object of the invention is to provide a form of boost and throttle control which is eifective for all conditions of operation. 1

According to this invention there is provided in an internal-combustion engine, the combination with two supercharging blowers arranged in series, 01" a throttle-valve on the inlet of each blower, and means which selectively renders either valve operative and holds the other in or near its fully-open position. Preferably the invention comprises the combination with an englue-driven blower, an auxiliary blower and means for rendering operative the auxiliary blower, of an operative connection between said blower and the throttle-valves, as above de-'- scribed, whereby the valve of the auxiliary blower is held open when that blower is inoperative.=

The auxiliary blower may be driven by the engine through a clutch, in which case there is provided the combination with the clutch-control lever of a rocking shaft operated thereby to connect a single throttle' control lever to one or other of the throttle-valves.

, According toanotherfeature this invention, the arrangements above described are applied to vinduction system atthe dischargeside' of the second-stage blower, a connection between the said,device and the engine throttle-valve and means operable by the pilot to adjust the said throttle-valves controlled by a variable-datum:

device in such manner that, despite variations in conditions of flight below a certain altitude, the valve is automatically maintained at such a setting that the pressure of the charge admitted to the engine cylinders corresponds to the position of the pilots adjusting-means. The connection between the pressure-responsive device and the throttle-valve is usually by way of a relay and there may or may not has direct mechanical co ection between the pilots lever and the throttle-valve. Where such interconnection exists the action of the pressure-responsive device is superimposed upon it.

The invention also comprises various arrangements of variable-datum boost-control, as here inai'ter described. r

In the accompanying drawings: 1 Figure 1 is a purely diagrammatic representation of the apparatus according tothe present invention, embodying a single pressure-responsive device for the variable-datum boost-control, and two hydraulic relay-devices selectively'controlled thereby for operating the throttle-valves,

Figure 2 is a diagrammatic representation of an arrangement including a single pressure-responsivedevice and hydraulic relay, with mechanical means for selectively operating the two throttle-valves,

Figure 3 is a diagrammatic representation of an arrangement including a single pressure-responsive device and two hydraulic relays, and

Figures 4, 5 and 6 are diagrammatic'representations of arrangements, each embodying two pressure-responsive devices and two hydraulic relays with various means for eifecting the selective operation.

Referring first to Figure 1, a radial-cylinder engine is indicated generally by the reference it having cylinders ll supplied through an intake il-from an engine-driven supercharging blower 1a. A throttle-valve u is situated in the intake to this blower, and the air-supply to the blower takes place through a carburettor l5 and an-auxiliary blower it having a throttle-valve il in its intake. in any convenient manner, througha clutch from the engine or by an exhaust-gas turbine together with'any suitable means for rendering such drive operative'or inoperative at will, such selection being'made by the pilot of the aircraft according to the power requirements or altitude of flight.

Other details, suchas an intercooler between the two blowers, will be used but are not concerned with this invention and are, therefore, not illus- 4 trated.

The auxiliary blower It may be driven A variable boost-control for the engine comprises a collapsible capsule l9 situated in a chamber [9 which is connected to the engineintake I 2 so that the pressure therein ls operative on the capsule. A further control of the capsule ls effected by the cam 20 on a pilot's control lever 2|, the position of the lever indicating the datum-setting for the capsule in the usual manner. I

The pilot's lever 2| is connected by a togglelinkage 22, 23 to the throttle-valve l4, also in the known manner, and the capsule I9 is also rendered operative on the throttle-valve through a hydraulic relay-device. The lower end of the capsule is coupled to a rod 24 on which there is pivotally mounted at the middle of its length a lever 29, and the ends 29, 21 of this lever respectively engage controlling valves 29, 29 of hydraulic relay-devices; these valves are of the usual type exhaust therefrom by conduits 33. The cylinder 3| contains.a piston 34 provided with a leakhole 39 and having its piston-rod 39 connected by a link 31 to the Joint of the toggle 22, 23.

The cylinder 32 contains a piston 39 with a leak-hole 39 and its piston-rod 40 is connected through a linkage 4!, 42, 43 with the throttlevalve I]. Each of the valves 29, 29 is provided with a controlling spring which tends to move it to its uppermost posltipn, and a rocking-shaft 44 is provided with two cams 49, 49 which are adapted to engage the upper ends respectively and alternatively of the valves 29, 29 so as to.

lever 49 is'operated by any suitable means to en-.

pression. The cam 49 thereupon releases the.

' valve 29, and the cam 49 engages the'valve 29 to press it downwards to such an extent that the relay-piston 34 is moved to its upper position in which it opens the valve 14 to a substantially fully-open position. The-varlable-datum boostcontrol is now operative through the lever on the valve 29 and thereby on the throttle-valve I! to maintain, in the usual manner, a definite boost-pressure for each setting of the lever 2|.

operative to cause movements to the valve l4 when the pilot adjusts the lever 2| but the linkage 31, 22, 23 is so-designed that such move- ;ments are small, andthat in its mean position the throttle-valve I4 is fully open. This arrangement, therefore, provides that when only the blower i3 is in'operation, the variable-datum boost-control is operative on the throttle-valve l4, and the throttle-valve I1 is held in its fully-- open position, and that if .the blower i9 is rendered operative to give the primary or firststage of compression, the valve i4 is held. in-a substantially fully-open position and the variable-datum boost-control operates only the throttle-valve l'l so that the control, so far as the pilot is concerned, is always the same whether one or two stages of compression are press them downwards. As illustrated, the cam 49 is holding the valve 29 downwards in such a position that the pressure-fluid is admitted to the underside of the piston 39 so as to force it to the top of its stroke and the cam 49 is turned to a position which is clear of the valve 29 to leave it free. This valve is, therefore, controlled by the lever 25 which, having its other end 21 held in a fixed position, determined by the cam 49, is under the control of the capsule l9, so that movements of the lower end of the. capsule upwards or downwards are imparted to the valve 29 in the normal manner of a relay-control by the pressure existing in the engine-intake l2.

By rotating the rocking-shaft 24, the cam 49 able linkage'4'l, 49 to a manually controlledv device 49 which is indicated as a lever, and is inter,-

used.

In the alternative form of this invention illustrated in Figure 2, a single variable-datum boostcontrol operates'selectively on the two throttlevalves: the collapsible capsule 59 controls in'the usual manner, through the valve 9|, the relaypiston 52, and the latter is connected through first and second throttle-valves 59, 99 and the selection between the two valves is effected by a means of cams 9|, 92 on a rocking-shaft 93 which 50. can be disengaged from the valve 29 and the connected with the driving means or control thereof for the auxiliary blower l9, and the arrangement is such that when the blower, I9 is inoperative, the cam 49 is engaged with the control-valve 29 so that it is inoperative.

At low altitudes of flight, the blower I9 is rendered inoperative by the lever 49 and, as explained above, the valve 29 is thereby held in such a position that the piston 39 is heldin its uppermost position in which, the valve I1 is held in its open position and is not controlled in any way alternatively engage abutments 94, to hold one or other throttle-valve in its fully-open position. When thus held, one end ofthe rocking-lever 59 is held stationary, and the variable-datum boost-control operates upon the other valve through the lever 99 in the normal manner. The rocking-shaft 93 controls, through an arm 99, the clutch or other means which renders the firststage blower operative or inoperative as desired.

In the alternative arrangement according to this invention illustrated in Figure 3, a single collapsible capsule 91 for a variable-datum boostcontrol operates two valves 99, 99 similarly and simultaneously, these valves, in turn, controlling respectively two relay-pistons 19, ill. The relay-piston 19 is connected to the mid-point of a toggle-linkage l2 connecting the pilot's control lever 13 with one of the throttle-valves 14, and the relay-piston connected through, any

suitable linkage with t "e second throttle-valve I9. I

The selective operation of the valves '84, I5 is effected by controlling the supply of pressure- .fiuid to the relay-cylinders; the pressure-fluid is supplied through the pipe 19 and a valve II by which it can be admitted to one or other of the pipes 18, 19 supplying the relay-cylinders respectively. 'I'hecontrollin'g lever 99 for this valve is interconnected with the clutch or other device which renders the auxiliary blower operain the normal manner.

tive or inoperative as desired. When the clutch is hydraulically controlled, the interconnection aforesaid may be provided by supplying pressure fluid to the clutch through the pipe 8| so that when the valve I1 is in the position shown, pressure-fluid is delivered to thepipesl9 and II so that the clutch is engaged and the relay-piston is supplied with pressure-fluid; no pressuresupply is given to the valve 98 and relay-piston- Ill and the spring 92 forces the piston III to the lever .l I: interconnected with the driving control for, the auxiliary blower. Wheh'the'auxiliary blower is rendered inoperative, as shown in Figure 6. the tappet H2 moves the capsule Ill downwards from engagement with its cam I09 and thereby movestherelay-valve Ill to'its lowermost position, in which case the hydraulic relay operatesst set the throttle-valve I I in its fully-open position. The movement of the lever upperlimit of its stroke, holding the valve It in substantially its fully-open position.

In yet another modification of this invention datum boost-controls, one for each throttleas illustrated in'Figure 4, two separate variablevalve, can be used. In this figure, the two 001- lapsible capsules are shown at 93, .M and the pilots control-lever 85 operates simultaneously on both of them through cams 8 5, 81 by means of the linkage 88c. Each capsule controls the relay-pistons 88, 89 respectively, in the usualtime shown, the pipe 95 is connected to the chamber 93 so that the capsule 83 is subjected to the boost-pressure of the engine and operates The chamber 94, however, is connected to the induction side of the mainblower by the pipe 95 and the low-pressure the chambers 93, 94 by the valve 92. In the posi- Ill which effects this operation simultaneously lifts the tappet Hi clear from its capsule I98 so as to leave the latter, under the control of its cam liiland thereby effect the normal control on the throttle-valve, H5. when the lever H9 is moved to its other position to render the aux-- iliary blower operative, the tappet H2 is lifted .clear of its capsule and the tappet ill isengaged with its capsule N19 to depress it and thereby cause the throttle-valve 9 to be moved to'its fully-open position whilst the normal boost-' control is operative on the auxiliary throttlevalve 5.

We claim: I 1. In an internal-combustion engine the combination of two supercharging blowers arranged in series, a throttle-valve on the inlet of each blower, and means which selectively renders either valve free to be operated by the usual controls and holds the other valve in or near its fully-open position.

2. Apparatus as set forthin claim 1 comprising an engine-driven blower, anauxiliary blower, means, for rendering operative the auxiliary blower, and an operative connection between, said means and the throttle valves, whereby the valve of the auxiliary blower is held open when at that point permits the capsule-94 to expand so that it moves its valve downwards, thereby applying pressure to the under side of the piston w and moving the valve 9| to its fully-open position. When the valve 92 is changed over to reverse the connections of the pipes 95, 99- with the chambers 99, 94, the relay .99 is thereby rendered-inoperative and the valve 90 is opened,

whilst the normal boost-control is effected on.

the valve 9|.

Figure 5 illustrates yet another modification of the present invention which is similar to that illustrated in Figure 4, in that two variabledatum boost-controls are used, one for each throttle-valve. The chambers 91, 98 for the two collapsible capsules are both subjected to the pressure in the inlet-manifold of the engine, and their selective operation is determined bycontrolling the supply of pressure-fluid to their relay-valves 99,109 respectively by means of avalve llil which operates injthe same way as the valve 11 described with reference to Figure 3.

' Asshown, pressure-fluid is being supplied to the valve 99, but is cut off from the valve ill and the spring I02, therefore, forces the'piston 103 to its uppermost position, moving the throttle-'- that blower is inoperative.

3. In an internal combustion engine the combination of two supercharging blowers arranged in series, a throttle valve on the inlet of each blower, means which selectively renders either valve free to be operated by the usual controls and holds the other valve in or near its fully open position, said blowers comprising an engine driven blower, and an auxiliary blower, an operative connection between said means and the throttle valves whereby the valve of the auxiliary blower is held open'when that blower is inoperative, said blower being driven by the engine through a clutch, the combination with the clutch control lever, of a rocking shaft operated thereby to connect a. single throttle control lever to one or other of the control valves.

4; In an internal combustionengine the combination oiE-twe supercharging blowers arranged in series,.'.;a throttle valve on the inlet of each,

.blower, meanslwliich selectively renders either valve free to be operated by the usual controls driven blower, and an auxiliary blower, an operative connection between said means and the throttle valves whereby the valve of theauxiliary valve I04 to its fully-open position, the normal 1 control being maintained on the other throttlevalve 105.-

' In yet another modification illustrated in Figure 6, two separate variable-datum boost-con trols are again used, and the two collapsible capsules llit, m are both subject to boost-pressure continuously, and they are provided with the usual controlling cams I99, I09 operatedby the pilots control-lever I III. A mechanical override for each of the cams is provided by tappets ill, 2, respectively, whichare operated by a blower is held open when that bloweris inoperativ'e, said throttle valves being controlled by a variable-datum boost. control.

5, Apparatus according to claim 4, comprising a single collapsible capsule subjected to the in- .duction pressure in the engine manifold, and

operating on a, floating lever at the middle of its length, two relay-devices whereof the valves are coupled respectively to the ends of said lever, and the relay-pistons are coupled respectively to the two throttle-valves, a rocking-shait having. two cams which alternatively engage the ends of the floating lever and rock it to a limiting position wherein the'free end is operated by the capsule and controls its relay-valve, and a con-' nection between saidrocking-shaftand the drive oithe auxiliary blower.

6. Apparatus according to claim 4, comprising a' single collapsible capsule, a single relay device controlled thereby and means for selectively coupling it to one or other of the throttle-valves.

"'L- Apparatus according to claim 4, comprising a single collapsible capsule, two relay devices controlled thereby, and operating respectively on the two throttle-valves, means for selectively supplying pressure-fluid to one or other of said relays, and means whereby the relay which is not thus energized, moves to its limiting position to open its valve. v

8. Apparatus according to claim 4, comprising a separate and complete variable-datum messesboost-control for each throttle-valve and means for selectively subjecting the collapsible capsule thereof to the induction pressure in the engine manifold.

9. Apparatus according to claim 4, comprising a separate and'complete variable-datum boostcontrol for each throttle-valve and means for selectively supplying pressure-fluid to the relaydevices thereof.

10. Apparatus according to claim 4, comprising two complete variable-datum boost-controls, one

for each valve, tappetsarranged selectively to engage the collapsible capsules and disengage one or other from its datum-varying cam, said tappets being operated by or with the control means for the drive of the auxiliary blower.

IVO BANKS MARPIES. HORACE NATHANIEL GORREIL. 

